In recent years, a wireless communication system has been implemented in plants or factories. The wireless communication system includes installed on-site devices for a wireless communication such as measuring devices, and operation devices, referred to as wireless field devices. The wireless communication system communicates a control signal for controlling wireless field devices and a measurement signal obtained by the wireless field devices via a wireless network. Communication standards used in the wireless communication system can, for example, be industrial wireless communication standards such as ISA100.11a or Wireless HART (registered trademark).
In order to join the wireless devices such as the wireless field devices into the wireless network, an operation is performed for setting the wireless devices with a set of device information such as setting data: network parameters and security parameters, which is referred to as provisioning. The methods of the provisioning can be broadly classified into an OTA (Over The Air) provisioning and an OOB (Out-Of-Band) provisioning. The OTA provisioning includes a process for setting a set of device information using the wireless communication via the wireless network. The OOB provisioning includes a process for setting a set of device information using a different communication from the wireless communication via the wireless network, wherein the different communication can be, for example, cable or wired communications and infrared communications.
For joining into the wireless network, the wireless devices, to which the provisioning has been performed, transmit a join-request, such as the join-request into the wireless network, to a management device of the wireless communication system. The management device receives the join-request and then performs an authentication using information included in the join-request, for example, a join key. If the authentication succeeds, then the management device permits the wireless devices, which transmitted the join-request, to join into the wireless network. If the authentication fails, the management device rejects the wireless devices to join into the wireless network. In this way, the joining into the wireless network is performed.
Patent Reference 1 discloses an example of the provisioning for the wireless devices to join into the wireless network, wherein the provisioning is the OTA provisioning. Patent Reference 2 discloses an example of the provisioning for the wireless devices to join into the wireless network using the provisioning devices such as device information setting tools, wherein the provisioning is the OOB provisioning.
The OOB provisioning is performed in such a state that the provisioning devices connect with or close to targeted wireless devices. Therefore, there are some problems that in a case that the targeted wireless devices are installed in a place such as an explosion-proof area where explosion-proof is required, it is difficult that the provisioning devices connect with or close to the wireless devices because of explosion-proof. Even if the performance targeted wireless devices are installed in a place where the explosion-proof is not required such as non-explosion-proof area, there are some problems that it is difficult that the provisioning devices connect with or close to the wireless devices depending on an installed area of the wireless devices. For example, if the wireless devices are installed on a high place, the provisioning workability is sometimes remarkably decreasing.
When the OOB provisioning is performed, the information, which is set to the wireless devices by using the provisioning devices, also needs to be set to the management device of the wireless communication system. The provisioning is the operation performed by on-site workers. The information setting to the management devices is the operation performed by persons such as plant operators who is different from the on-site workers. Therefore, after the provisioning for the wireless devices was completed, then the on-site workers have to hand over the information which was set to the wireless devices to the plant operators. However, if the information to be handed over is not handed over between the on-site workers and the plant operators, any confusion can occur.
In contrast, the OTA provisioning is performed by the wireless communication via the wireless network. Thus, the provisioning may be performed regardless of whether or not the wireless devices are installed in the explosion-proof area. However, the OTA provisioning uses wireless signals having the same frequency band as for the wireless network. Thus, there can be caused an interference with the wireless communication in the wireless network.